Greetings,
@Kasamoto I think this being the 318ti org forums, its not really specializing discussing the e46 or 330i or 6 cylinder engines. Its a question best asked elsewhere I would say or you could email directly the manufacturer of the kit.
a lot of information online counter each other and its good to do a lot more research, there are a lot of things coming into play in the math. From our own tests we found the M62 when setup properly will be sufficient to provide a good 70HP - 100HP power increase depending on the engine and tune. This is true for the M54B30 as well.
The efficiency of the supercharger also comes into play. Also one must ask, will the engine be stock? Will it be built to handle more power to justify a bigger supercharger or a turbo? If its stock and the ECU is also, and you never plan to build it and keep it reliable, then the answer is simple a smaller supercharger that does not push you to the limits is what you want. For that there is the V3.62 Kit of course which gets you some 6-8PSi with an air to air intercooler. if that is the kit in question then its really best to email. Hope that helps.
If anyone is interested, there is Summer Sale with a a massive 22% discount on all the kits at the official Hyde Motor Works Shop. 
